Morphological evidence of paracellular transport in perfused rat submandibular glands

The morphological change of the paracellular route for fluid secretion is still a long-standing question. The purpose of this study was to visualize alterations in the cytoskeleton structure of tight junctions caused by carbachol (CCh) and isoproterenol (IPR) treatment of perfused rat submandibular glands (SMGs), using freeze-fracture (FF) replicas of rapidly frozen tissues. Isolated SMGs from male Wistar rats were perfused and stimulated with 1 μM CCh and IPR. Specimens were immediately rapidly frozen with liquid helium by metal contact. After cutting and deep etching, FF replicas were obtained by rotary shadowing and were examined by transmission electron microscopy. After CCh/ IPR stimulation, the strand particles of TJs rearranged with free ends and terminal loops. In the vertical fracture surface, cytoskeletal filaments beneath the plasma membrane were arranged in a thicker layer than those of the gland without stimulation. Contraction of the submembranous actin cytoskeleton during exocytosis elicited by CCh/IPR may cause rearrangement of TJ strands due to direct interactions between the TJ membrane particles and actin filaments via the tiny bridging structures. The rearrangement and movement of TJ membrane particles involves reconstruction of the subluminal membranous actin filament network through the intermediary of interstitial molecules and may modulate increased paracellular permeability after CCh/IPR stimulation

Pilocarpine-induced salivary fluid secretion in the perfused submandibular gland of the rat

Xerostomia is the symptom of dry mouth often seen in patients who receive head and neck radiation therapy or in patients who have Sjögren’s syndrome. The primary treatment to relieve xerostomia symptom is oral administration of pilocarpine, a parasympathomimetic agent with muscarinic action. Increase in salivary secretion induced by systemic administration of pilocarpine is considered to be mediated by actions on muscarinic cholinergic receptors in the central nervous system and salivary glands. In this study, we investigated the direct effect of pilocarpine on salivary fluid secretion in the isolated, perfused rat submandibular gland. Pilocarpine provoked salivary fluid secretion in a dose-dependent manner. The Na+-channel blocker tetrodotoxin had almost no effect on the pilocarpine-induced salivary fluid secretion, indicating that pilocarpine directly stimulates submandibular gland. Pilocarpine induced an increase in intracellular Ca2+ concentration in dispersed submandibular gland cells at 37℃, but not 25℃. The salivary fluid secretion induced by pilocarpine was consisted of a rapid and transient phase and a subsequent sustained phase, which profile was different from that evoked by carbachol, another typical muscarinic agonist. Pilocarpine also induced Lucifer yellow secretion via paracellular route

Morpho-Physiological approach to the paracellular route for salivary secretion by isolated perfused submandibular gland

A part of the salivary components are shifted from the blood via a trans- and/ or paracellular route. The isolated, arterially perfused, salivary glands (submandibular and parotid glands) were used to assess paracellular transport functionally and morphologically. In the present study, the hydrostatic pressure of the perfusion was changed and the fluid secretion and paracellular transport of fluorescent dye in the isolated perfused submandibular gland were examined. The present findings lead to the conclusion that part of the paracellular transport could be driven by hydrostatic pressure, and that fluid movement drags the solutes

An Analysis of Mutual Communication between Qubits by Capacitive Coupling

A behavior of a two qubit system coupled by the electric capacitance has been studied quantum mechanically. We found that the interaction is essentially the same as the one for the dipole-dipole interaction; i.e., qubit-qubit coupling of the NMR quantum gate. Therefore a quantum gate could be constructed by the same operation sequence for the NMR device if the coupling is small enough. The result gives an information to the effort of development of the devices assuming capacitive coupling between qubits.Comment: 8 pages, 2 figures Revised and Replaced on Apr. 8 200

CT findings of type A acute aortic dissection that did and did not result in prehospital death

The differences between the pathologies of cases of type A acute aortic dissection (AAD) that did and did not result in prehospital death (PHD) have not been fully elucidated. This study aimed to compare the CT findings and clarify the differences between the pathologies of such cases. Ninety four consecutive type A AAD patients between 2010 and 2020 were enrolled in this study. There were 47 males and 47 females (mean age: 69.0 ± 14.4 years). The patients were divided into those that did (n = 25, 27%) and did not (n = 69, 73%) suffer PHD. We retrospectively evaluated the CT or postmortem CT findings of each case and analyzed the relationships between clinical factors (CT findings and clinical characteristics) and PHD using logistic regression analysis.Bloody pericardial effusion (96% vs 35%, P < .0001), bloody pleural effusion (40% vs 1%, P < .0001), and mediastinal hematomas (88% vs 14%, P < .0001) were significantly more common in the PHD group than in the no PHD group. In the multivariate logistic regression analysis, bloody pericardial effusion and lung consolidation were found to be significant risk factors for PHD (odds ratio: 21.29 [95% confidence intervals {CI}: 1.19–248.29] and 13.72 [95% CI: 1.79–105.06], respectively; P = .014 and P = .012, respectively). AD affecting the abdominal aorta was identified as a significant negative risk factor for PHD (odds ratio: 0.02 [95% CI: 0.01–0.65]; P = .0042). Most PHD due to type A AAD are associated with hemorrhaging. Bleeding into the pericardium and type A AAD confined to the thoracic aorta are significant risk factors for PHD. Secondary respiratory failure might contribute to PHD in such cases

Characterization of neurokinin A-evoked salivary secretion in the perfused rat submandibular gland

Neurokinin A (NKA) evokes salivary secretion. Despite such reports, the direct effect of NKA on salivary secreteion in submandibular gland has not been clarified. Here we studied characterization of salivary fluid secretion induced by NKA in the perfused submandibular grand (SMG) of the rat. NKA (3-100 nM) stimulated salivary fluid secretion in a dose-dependent manner. The profile of secretion induced by NKA consisted of two phases, transient and sustained phases. When the gland was perfused with Lucifer yellow (LY)-containing perfusate buffer and stimulated by NKA, concentration of LY in saliva was increased. In the absence of Ca2+ in the perfusate, NKA induced only a transient salivary fluid and a transient LY secretion. When the gland was treated with BAPTA, NKA failed to induce both salivary fluid secretion and LY secretion. These results suggest that NKA induces salivary secretion via both transcellular and paracellular pathways, which depends on intracellular Ca2+ mobilization

Impact of transport pathways on the time from symptom onset of ST-segment elevation myocardial infarction to door of coronary intervention facility

AbstractBackgroundReducing total ischemic time is important in achieving better outcome in ST-segment elevation myocardial infarction (STEMI). Although the onset-to-door (OTD) time accounts for a large portion of the total ischemic time, factors affecting prolongation of the OTD time are not established.PurposeThe purpose of this study was to determine the impact of transport pathways on OTD time in patients with STEMI.Methods and subjectsWe retrospectively studied 416 STEMI patients who were divided into 4 groups according to their transport pathways; Group 1 (n=41): self-transportation to percutaneous coronary intervention (PCI) facility; Group 2 (n=215): emergency medical service (EMS) transportation to PCI facility; Group 3 (n=103): self-transportation to non-PCI facility; and Group 4 (n=57): EMS transportation to non-PCI facility. OTD time was compared among the 4 groups.Essential resultsMedian OTD time for all groups combined was 113 (63–228.8)min [Group 1, 145 (70–256.5); Group 2, 71 (49–108); Group 3, 260 (142–433); and Group 4, 184 (130–256)min]. OTD time for EMS users (Groups 2 and 4) was 138min shorter than non-EMS users (Groups 1 and 3). Inter-hospital transportation (Groups 3 and 4) prolonged OTD by a median of 132min compared with direct transportation to PCI facility (Groups 1 and 2). Older age, history of myocardial infarction, prior PCI, shock at onset, high Killip classification, and high GRACE Risk Score were significantly more frequent in EMS users.Principal conclusionsSelf-transportation without EMS and inter-hospital transportation were significant factors causing prolongation of the OTD time. Approximately 35% of STEMI patients did not use EMS and 21% of patients were transported to non-PCI facilities even though they called EMS. Awareness in the community as well as among medical professionals to reduce total ischemic time of STEMI is necessary; this involves educating the general public and EMS crews

Clinical Significance of Serum Antithrombin III Activity After Hepatectomy for Hepatocellular Carcinoma

[Background] As antithrombin III (AT-III) is produced in the hepatocytes, its serum activity decreases at the time of liver failure, in addition to ischemia reperfusion injury, vascular endothelial dysfunction, and disseminated intravascular coagulation (DIC). Here, we examined whether the serum AT-III value after hepatectomy could be a prognostic factor for hepatocellular carcinoma (HCC). [Methods] Of 141 patients who underwent hepatectomy for HCC, data for 101 patients in whom serum AT-III activity was measured on the first postoperative day were extracted. Patients with serum AT-III activity > 50% and ? 50% were assigned to high value (72 cases) and low value (29 cases) groups, respectively. We examined the clinical and prognostic differences between these two groups. [Results] The average age of enrolled patients (83 men and 18 women) was 68.0 years. The 5-year overall survival rate was 88% and 60% in the high and low value groups, respectively (P < 0.01). Furthermore, the 2-year relapse-free survival rate was 71% and 54% in the high and low value groups, respectively (P = 0.03). [Conclusion] This is the first study to demonstrate that serum AT-III levels on the first postoperative day may serve as a prognostic factor in HCC patients